1. Field of the Invention
The present invention relates to an apparatus for, and method of, processing video signals, and more particularly, to an apparatus for, and method of, adaptively processing video signals according to noise a state, in which coefficients of a filter are optimally adjusted according to the magnitude of a noise included in an input video signal and then the input video signal is filtered by the adjusted filter.
2. Description of the Related Art
Related video signal processing techniques are disclosed in Korean patent No. 1999-2523 and Japanese patent No. 2002-341850. Japanese patent No. 2002-341850 discloses a technique in which the contrast of an input video signal is adjusted by a video amplifier and high frequency noise of signals output by the video amplifier are removed by a low pass filter, so that the contrast of the video signal can be adjusted without being affected by noise.
Korean patent number 1999-2523 discloses a technique to enhance the brightness distributional characteristic of an image in a histogram conversion of a probability density function of an image brightness level by selecting a reference histogram with respect to a histogram of an original image, comparing the accumulated distribution function of the reference histogram with that of the histogram of the original image to generate a conversion function, and applying the conversion function to the original image.
Typically, an apparatus for processing video signals uses a noise-suppression filter to remove noise in an input video signal. However, in the noise-suppression filter, since its tap coefficients are fixed regardless of the noise state, video quality is deteriorated as the noise state changes.